Metallic materials micro-embossed with laser-generated patterns are incorporated into various label structures and printed with ink patterns that complement the laser-generated patterns.
Prismatic labels combine holographic effects of micro-embossed metallic materials with conventional printing to present dynamic images that flash through a range of colors. Conventionally embossed holographic patterns vary visually with line of sight. Conventional printing does not. Together, printing over holographic patterns provides more stable imagery whose reflective characteristics and colors vary with line of sight.
The metallic materials are typically metalized film or paper materials that have bright reflective surfaces. Lasers micro-emboss repeating patterns of grooves into a supporting structure of the metallic material to diffract light striking the metallic material into chromatically dispersed images. Printing inks overlying the holographic patterns can be opaque or translucent. The opaque inks block any effects of the underlying holographic patterns to provide stable image portions. The translucent inks provide color filters through which the holographic effects are still evident.
Prismatic label construction starts with a choice of micro-embossed metallic material that exhibits desired holographic effects such as repeating rainbow or star patterns. The metallic material, which has the form of a continuous web, can be coated with a layer of pressure-sensitive adhesive and laminated to a release liner. Now in the form of a prismatic label stock, further conversion into prismatic labels is achieved by printing on the holographic surface and die cutting the metallic material into individual labels.
A considerable capital investment is required to form the micro-embossed metallic material into prismatic label stock. In addition, prismatic label stock is processed in much smaller quantities than conventional label stock because of the much wider uses for conventional label stock. Accordingly, the cost of prismatic label stock is much higher, which tends to limit its use.
My method of making prismatic labels significantly reduces their cost while providing improved construction opportunities as well as cost-effective construction alternatives for meeting different market demands. The cost reductions are achieved by exploiting the much lower costs of conventional label stocks. In addition, the wider variability of conventional label stocks, such as for making piggyback labels or redeemable coupon labels, is further exploited for making such constructions available in prismatic forms.
An in-line printing method of making pressure-sensitive prismatic labels according to my invention includes advancing both a web of micro-embossed metallic material and a web of conventional label stock along an in-line press. The conventional label stock has a substrate that is coated with a pressure-sensitive adhesive and is laminated to a release liner. The two webs are bonded together with adhesive and further advanced through a plurality of in-line printing stations that print a succession of patterns on the web of micro-embossed metallic material so that holographic effects of the embossed metallic material remain evident through at least some of the printing. Repeating patterns are cut through both the web of micro-embossed metallic material and the substrate of the label stock to define individual pressure-sensitive prismatic labels.
Both the substrate of the label stock and the adhesive required to bond the substrate together with the micro-embossed metallic material constitute additional layers beyond those normally assembled for constructing pressure-sensitive prismatic labels. However, cost savings from acquiring conventional label stocks over available prismatic label stocks more than offset any costs attributable to the additional materials.
The micro-embossed metallic material is preferably a metalized film in which a metal such as aluminum or zinc is deposited onto a film such as a polypropylene, polyethylene, polystyrene, polyester, or polyvinyl chloride. The label stock substrate is preferably paper. When bonded together, the metalized film and paper substrate form stronger and more durable labels. The paper substrate contributes increased rigidity, and the metalized film contributes tear resistance and an environmental barrier.
Film-based label stocks can also be used, especially for particularly adverse (e.g., wet) environments. For example, the metallic material in the form of a metalized film can be bonded to a label stock made of polyolefin for eventual mounting on squeeze bottles or other flexible substrates. A wide choice of adhesives is also available with conventional label stocks, which would otherwise be impractical to make available in the form of prismatic label stock. The adhesives can vary in qualities such as co-adhesion, repositionability, removability, and resistance to cold.
The in-line printing preferably includes (a) applying an opaque ink in a succession of patterns for blocking holographic effects of the micro-embossed metallic material in limited areas of the embossed metallic material and (b) applying a translucent ink in a succession of patterns for chromatically filtering holographic effects of the micro-embossed metallic material in other limited areas of the embossed metallic material. The printing stations for applying both the opaque ink and the translucent ink are preferably flexographic printing stations.
The conventional label stock can take a variety of forms for extending prismatic label construction into uses that would otherwise be even less economically viable. For example, the label stocks can vary from single card stocks to piggyback or redeemable coupon label stocks that involve additional substrates and layers of adhesive. In addition, the same micro-embossed metallic material can be bonded to a plurality of different conventional label stocks, which are available in smaller quantities; or more than one micro-embossed metallic material can be bonded to the same label stock.
More efficient use of the micro-embossed metallic material is achieved by bonding the metallic material to limited portions of the conventional label stock. For example, the web of micro-embossed metallic material can be narrower than the web of conventional label stock so that the metallic material covers only a portion of the width of the label stock. Conventional printing can be applied to both the metallic material and the exposed portion of the conventional label stock. The adhesive, which bonds the metallic material to the label stock, can be applied in a pattern in registration with a die cutting station so that the metallic material can be applied to the conventional label stock in a succession of closed shapes.